Hey everyone, So I have had KSP for awhile now and got my orbiting down so I thought i'll take a pop at a mun landing. So, as usually I got in a low parking orbit around Kerbal (71,234/96,721) then I commenced the inter-planetary burn. Which put me on course to encounter the gravity of mun. All went well until I was about to put my retrograde burn on. Aligned myself to the retrograde vector and then tried to start my burn.... The engine didn't fire at all. Now from previous experience I thought it was a power issue (but this time I installed to solid panels and a battery box on the back of the command module, which was also fully powered at the time). Then I thought it could be the fact the stage was burnt out, so ditched the stage and started the next. Still nothing. I would be very great full if someone could give me pointers, thanks